Ultrasensitive Exhaled Breath Sensors Based on Anti-Resonant Hollow Core Fiber with In Situ Grown ZnO-Bi2O3 Nanosheets

Combination of anti-resonant hollow-core fiber (HCF) and semiconductor nanomaterial is an effective strategy to obtain high-performance gas sensors with exceptional sensitivity and low power consumption. However, controlling the semiconductor morphology onto HCF is a major challenge to achieve the desired gas sensor with the enhanced sensitivity. Here, a ZnO-Bi2O3 nanosheets (NSs) heterostructure is grown in situ on the surface of HCF by sol-gel and hydrothermal methods. ZnO-Bi2O3 NSs serving as electron acceptors trap electrons after acetone adsorption and then change the refractive index of the surface of HCF. Benefiting from the unique sheet structure and the synergetic effects for multi-component, the resulting ZnO-Bi2O3 NSs enabled HCF gas sensor exhibits high sensitivity, selectivity, and repeatability for detecting acetone at room temperature, particularly in the low concentration range, with the theoretical limit of detection down to 140 parts-per-billion. Meanwhile, the successful application of the ZnO-Bi2O3 NSs enabled HCF gas sensor to distinguish the exhaled breath from the healthy individuals and simulated diabetic cases is demonstrated, which paves the way to achieve non-invasive, ultra-sensitivity gas sensing at room temperature for the early diagnosis of diabetes.

Automated summary

The combination of ZnO-Bi2O3 nanosheets heterostructure grown on the surface of HCF enables the gas sensor to exhibit high sensitivity, selectivity, and repeatability for acetone detection at room temperature, particularly in the low concentration range. The successful application of the ZnO-Bi2O3 nanosheets on HCF also allows the sensor to distinguish exhaled breath from healthy individuals and simulated diabetic cases, paving the way for non-invasive, ultra-sensitive gas sensing at room temperature for early diabetes diagnosis.